1. Field of the Invention
This invention relates to electrical connectors, and more particularly relates to improvements in the design of contacts for use in electrical connectors.
2. Description of the Prior Art
Many electrical connectors currently on the market include a pair of assemblies which cooperatingly mate to provide an electrical conductive path through the connector. One assembly of the connector may include one or a number of conductive pins or posts (generally called pins). Each pin is mounted at one end in the assembly (generally called a plug or pin connector) in a variety of different ways; the other end of each post is free standing. The other assembly of the connector includes one or a number of conductive resilient arms or leaves (generally called contacts), each contact corresponding to a pin of the pin assembly. The resilient contacts also are mounted in their receptacle assembly with one end of each contact free.
The pins and resilient contacts of the two assemblies are aligned so that, when the two assemblies of the connector are coupled together, each pin engagingly contacts the corresponding resilient contact.
Each resilient contact is biased by its resilience to assert sufficient contact pressure on the outer surface of its mating pin. Typically, the contacts are positioned in their rest state to extend partially into the axial path of the pins when the two connector assemblies are aligned but not yet coupled. The pins deflect the resilient contacts as the two connector assemblies are joined together, so that the resilience of the contact presses it against the mating pin post. This ensures a proper electrical path through the mating contacts of each connector assembly.
One of the problems with the conventional connectors having the structure described above is that their useful life is limited in number of connecting and disconnecting operations due to premature contact wear. This problem has especially manifested itself in applications where gold, platinum, iridium, rhodium or other noble or precious metals are suitably placed or coated (as by plating, rolling, filling, layering or the like) on electrical contact-making surfaces of the pins and resilient contacts, in order to make the connector more immune to corrosion and other environmental conditions and to reduce the electrical resistance of the pin-to-contact connection. The coated contact surfaces of the pins and resilient contacts may eventually be abraded by the sliding engagement of the contacts, and worn away as the connector is repeatedly connected and disconnected. This leaves the untreated undermaterial of the contacts exposed, so that they may corrode and result in an impaired conductive path through the connector, rendering the connector unacceptable for use after a shorter-than-desired connect/disconnect cycle life.
One way to extend this cycle life is to use a thicker layer of noble metal. However, this is undesirable because of the consequent substantial increase in material costs.